* {
    margin: 0;
    padding: 0;
    list-style: none;
}

body {
    overflow: hidden;
    background-color: #000;
}

.balloon {
    position: absolute;
    width: 160px;
    height: 160px;
    background-color: #f9f9f9;
    /*画气球*/
    border-radius: 160px 160px 64px 160px;
    /*旋转45度*/
    transform: rotate(45deg);
    /*加阴影*/
    box-shadow: -8px -8px 80px 8px #873940 inset;

}

/*伪元素after*/
.balloon:after {
    position: absolute;
    bottom: 0;
    right: 0;
    content: '';
    border: 8px solid transparent;
    border-right-color: #873940;
    transform: rotate(45deg);
    border-radius: 50%;
}
